Display systems may broadly include emissive displays and non-emissive displays. An emissive display refers to a display capable of producing an image directly without requiring a backlight. Research in field emission displays, for example, provide various exemplary types of emissive displays. Other types of displays, such as light-emitting diode (LED) displays, organic light-emitting diode (OLED) displays, surface-conduction electron-emitter displays (SEDs) and the like, may also be generally referred to as emissive displays. A non-emissive display, on the other hand, refers to a display that requires a light source. Light modulating display devices, such as liquid crystal displays (LCDs), for example, are non-emissive displays.
A “fail-operational” system refers to a system that can continue to operate even after a failure has occurred. Operation after failure is required for many aircraft systems, including display systems for delivering critical primary flight information. A conventional implementation of an aircraft display system typically includes multiple displays horizontally positioned across an instrument panel. These displays are secured to fixed locations and cannot be repositioned. Some of the adjacent displays may have abilities to enter a reversionary mode and serve as a backup to a primary display in case of a primary display failure. The ability for an adjacent display to enter a reversionary mode may allow a pilot to maintain aircraft control and proceed in a degraded state.
It is noted, however, that the location of the adjacent display (now serving as a backup to the primary display) is sub-optimal compared to the location of the primary display. Using a backup display located at a sub-optimal location has several disadvantages. For instance, relocation of the primary flight information on the instrument panel may impact pilot's cross-check habit patterns and may result in extended visual search during periods of high workload. The pilot may also be required to perform additional actions in order to view detailed system information due to the display being used in the reversionary mode. In addition, the need for having to equip an instrument panel with multiple displays (so that adjacent displays can serve as backups) may contribute to added weight and excessive instrument panel clutter. Furthermore, a display that may serve as a backup display needs to be configured in a manner that can maintain readability across an extended field of view, resulting in the need for additional power or added unit cost.
It is also noted that recent development in flight deck designs are increasingly dependent on single large displays. There may not be an adjacent display available that is capable of serving as a backup to a single large display, and it may therefore be essential to design such a single large display to be fail-operational.